The Prosecco R Short-Sleeve Base Layer Top delivers moderate insulation without adding much weight or bulk. The mid-weight Prosecco fabric wicks moisture away from your skin to keep you warm and dry, even during more intense training sessions. It can be worn under a short sleeve jersey for the cool temperatures of early fall, or under a full-length jacket to extend your riding season well into winter. The form-fitting cut is designed to fit under Castelli jerseys, but works well as a base layer for any cold weather kit. Castelli prioritizes comfort by incorporating flat seams throughout the garment, ensuring there's no irritation from pesky protruding seams.